The long-term objective is to determine whether prolonged GH administration can reduce postprandial glucose levels in viscerally obese adults with impaired glucose tolerance IGT). IGT increases the risk for developing 2 major health problems, type 2 diabetes mellitus and cardiovascular disease, and this risk decreases when postprandial glucose reduction is achieved. The specific aim is to determine if GH administration in viscerally obese adults with TGT will result in (1) a reduction in visceral fat and (2) lower postprandial glucose levels after a 75 gm glucose load. Men and women between the ages of 40 and 75 with visceral obesity and IGT will be recruited to participate. During weeks 0-8, subjects will receive a thiazolinedione (TZD) or oral placebo to determine if TZDs can overcome the transient insulin resistant effects of GH during the first few weeks of treatment. During weeks 8-32, recombinant human GH or a subcutaneous placebo will be co-administered with TZD or placebo. Changes in visceral body tat will be determined with CT scan and waist circumference measurements. Changes in postprandial glucose levels before and after 6 months of GH treatment will be determined using a 75 gm oral glucose tolerance test.